1. Technical Field
Exemplary embodiments of the present invention relate to an electromechanical transducer element, a liquid droplet discharge head to discharge liquid droplets using the electromechanical transducer, and an image forming apparatus including the liquid droplet discharge head.
2. Background Art
As an image forming apparatus, an inkjet recording apparatus including an ink droplet discharge head to discharge ink droplets to form images on a medium, such as a sheet of paper, while conveying the medium by adhering the ink droplets thereon is known.
The liquid droplet discharge head includes nozzles to discharge liquid droplets of a liquid such as ink; a liquid chamber (which may be denoted as a pressure chamber, a discharge chamber, and the like) to communicate with the nozzles and containing a liquid; and an electromechanical transducer such as a piezoelectric element. The piezoelectric element (to which a drive voltage is applied) included in the liquid droplet discharge head vibrates to deform a diaphragm that forms one wall of the liquid chamber, so that the deformation of the diaphragm squeezes the liquid inside the liquid chamber, thereby enabling to discharge liquid droplets from the nozzles.
The liquid droplet discharge head employs a piezoelectric actuator that employs a bending vibration mode and has a construction in which the piezoelectric element, including a lower electrode, a piezoelectric member, and an upper electrode laminated one atop the other, is disposed on the diaphragm.
As a method of manufacturing the liquid droplet discharge head, a semiconductor device production technology adapting the Micro-electromechanical System (hereinafter, MEMS) is used. The production method using MEMS includes forming a diaphragm on one side of a substrate that forms a partition wall of the liquid chamber. On the diaphragm, a lower electrode film to form the lower electrode, a piezoelectric member film to form the piezoelectric member, and an upper electrode film to form the upper electrode are sequentially formed. Each film is subjected to resist pattern formation by photolithography, etching, and resist separation using a chemical liquid to form a piezoelectric element including the lower electrode, piezoelectric member, and upper electrode each layer laminated in layers with a predetermined pattern. With this structure, a piezoelectric actuator substrate as an electromechanical transducer with a plurality of piezoelectric elements each formed in a predetermined pattern can be obtained.